I'm Fabio I'll assist you today.
Change the burning speed to a lower speed 16x or 8x should work.
Click the Recording Options pull-down menu and choose Recorder Settings.The recorder settings also appear when you click the red Record button. Click the Basic tab to change basic recording settings, including the Write Speed
Hi there, my name is ***** ***** I'll try to help you with the problem.
Sorry, I have a few questions first. Do all 4 DVD's have a VIDEO_TS folder that you're copying from?
I guess maybe you're not online, so let me leave some instructions here that you can try. I think you need to get Roxio to extract the video from the VIDEO_TS file before you create the composite DVD if it's not already doing that. You should be able to choose the titles you want from the VIDEO_TS folder using the Media Browser. I think that will force it to extract the video.
When you write the composite DVD, try writing it as a Disk Image
Please give that a try and let me know if it works or not. If it doesn't, and we can both be online at the same time, we can try a few more options.